Abstract: TiC reinforced titanium matrix composites were produced by non-consumable arc-melting technology utilizing the selfpropagation high-temperature synthesis (SHS) reaction between titanium and graphite. X-ray diffraction (XRD) was used to identify the phases in the composites. Microstructures of the composite s were observed with optical microscope (OM) and transmission electron microscope (TEM). The results show that there are two phases in the composites: TiC and titanium matrix alloy. TiC shows two different shapes: dendritic shape, equiaxed or near-equiaxed shape. The in situ synthesized TiC grows in a way of dissolution-precipitation. Analysis of binary phase diagram determined that the solidification path undertook the following three stages: primary TiC, binary eutectic β-Ti+TiC and solid transformation. Primary TiC grows in dendritic shape due to the formation of composition undercooling. Binary eutectic TiC grows in equiaxed or near-equiaxed shape. A small quantity of TiC may form twin structure during nucleation and growth. The twin plane is (111) plane.
Microstructural characterization of TiC in in situ synthesized titanium matrix composites
Abstract:
TiC reinforced titanium matrix composites were produced by non-consumable arc-melting technology utilizing the self-propagation high-temperature synthesis (SHS) reaction between titanium and graphite. X-ray diffraction (XRD) was used to identify the phases in the composites. Microstructures of the composites were observed with optical microscope (OM) and transmission electron microscope (TEM) . The results show that there are two phases in the composites: TiC and titanium matrix alloy. TiC shows two different shapes: dendritic shape, equiaxed or near-equiaxed shape. The in situ synthesized TiC grows in a way of dissolution-precipitation. Analysis of binary phase diagram determined that the solidification path undertook the following three stages: primary TiC, binary eutectic β-Ti+TiC and solid transformation. Primary TiC grows in dendritic shape due to the formation of composition undercooling. Binary eutectic TiC grows in equiaxed or near-equiaxed shape. A small quantity of TiC may form twin structure during nucleation and growth. The twin plane is (111) plane.